MAAS bridge script does not explicitly parse new alias syntax in MAAS 2.1

[Andrew McDermott]

Using MAAS 2.1 (and curtin 0.1.0~bzr425-0ubuntu1~16.04.1) I notice the format of aliases has changed from using ':' as a indicator to repeating the 'iface' stanza - which is a perfectly reasonable thing to do.

However, Juju's MAAS bridging script was reliant on the old format.

An example alias now looks like:

auto ens3
iface ens3 inet static
  address 192.168.20.68/24
  gateway 192.168.20.2
  mtu 1500

# control-alias ens3
iface ens3 inet static
  address 192.168.20.69/24

We previously got 'ens3:1' for the alias and the bridge script looked for and parsed that syntax explicitly. When we run the script against the new format we now get:

auto ens3
iface ens3 inet manual
  mtu 1500

auto br-ens3
  iface br-ens3 inet static
  address 192.168.20.68/24
  gateway 192.168.20.2
  bridge_ports ens3

auto ens3
  iface ens3 inet manual

auto br-ens3
  iface br-ens3 inet static
  address 192.168.20.69/24
  bridge_ports ens3

which appears to work, though this is a sample size of 1.

For the moment this bug is raised for awareness of the change in format.

Looking on a machine I see the following:

$ brctl show bridge name bridge id STP enabled interfaces br-ens3 8000.525400ccead9 no ens3 br-ens4 8000.5254004b7d91 no ens4 lxdbr0 8000.000000000000 no

$ ip addr show br-ens3 | grep -w inet
                                                                                             inet 192.168.20.68/24 brd 192.168.20.255 scope global br-ens3 inet 192.168.20.69/24 brd 192.168.20.255 scope global secondary br-ens3

[Andrew McDermott (frobware)]

We have a similar[1] alias bug which may no longer need fixing in light of the curtin changes identified by this bug. This needs some investigation to understand where/when curtin version (0.1.0~bzr425-0ubuntu1~16.04.1) gets backported to.

[1] https://bugs.launchpad.net/juju/+bug/1631940

[Canonical Juju QA Bot (juju-qa-bot)]

This bug has not been updated in 2 years, so we're marking it Low importance. If you believe this is incorrect, please update the importance.